body {
        background-color:#edecec;
}
        /* basic menu styles */
        .nav-menu {
            display: block;
            background: #74adaa;
        	width:950px;
        	margin: 50px auto 150px;
        }
        .nav-menu > li {
          display: inline;
          float:left;			
        	border-right:1px solid #94c0be;
        }
        .nav-menu > li:last-child {
          border-right: none;
        }
        .nav-menu li a {
          color: #fff;
        	display: block;
        	text-decoration: none;
          /*调用本地字体*/
        	font-family: 'sansationregular';
          -webkit-font-smoothing: antialiased;
        	-moz-font-smoothing: antialiased;
        	font-smoothing: antialiased;
        	text-transform: capitalize;
        	overflow: visible;
        	line-height: 20px;
        	font-size: 20px;
        	padding: 15px 30px 15px 31px;			
        }
        
        
        .three-d {

          /* 任务三、设置3D舞台布景 */
        	perspective:200px;
        	-o-perspective:200px;
        	-webkit-perspective:200px;
        	-moz-perspective:200px;
        	-ms-perspective:200px;

          /*任务四、设置3D舞台布景过渡效果*/
        	transition:all 0.7s linear;
        	-o-transition:all 0.7s linear;
        	-ms-transition:all 0.7s linear;
        	-moz-transition:all 0.7s linear;
        	-webkit-transition:all 0.7s linear;
          position: relative;
        }
        
        .three-d:not(.active):hover {
          cursor: pointer;
        }
        
        /*任务五、给不是当前状态的3D舞台的悬浮与聚焦状态设置变形效果*/
        .three-d:not(.active):hover .three-d-box, 
        .three-d:not(.active):focus .three-d-box {
        	transform:translateZ(-25px) rotateX(90deg);
        	-o-transform:translateZ(-25px) rotateX(90deg);
        	-ms-transform:translateZ(-25px) rotateX(90deg);
        	-moz-transform:translateZ(-25px) rotateX(90deg);
        	-webkit-transform:translateZ(-25px) rotateX(90deg);

        }
        
        .three-d-box {
          /*任务六、给3D舞台中“.three-d-box”设置过渡与变形效果*/
			transform:translateZ(-25px);
        	-o-transform:translateZ(-25px);
        	-ms-transform:translateZ(-25px);
        	-moz-transform:translateZ(-25px);
        	-webkit-transform:translateZ(-25px);

        	transition:all .3s ease-out;
        	-o-transition:all .3s ease-out;
        	-ms-transition:all .3s ease-out;
        	-moz-transition:all .3s ease-out;
        	-webkit-transition:all .3s ease-out;


          -webkit-transform-style: preserve-3d;
          -moz-transform-style: preserve-3d;
          -ms-transform-style: preserve-3d;
          -o-transform-style: preserve-3d;
          transform-style: preserve-3d;
          -webkit-pointer-events: none;
          -moz-pointer-events: none;
          -ms-pointer-events: none;
          -o-pointer-events: none;
          pointer-events: none;
          position: absolute;
          top: 0;
        	left: 0;
        	display: block;
        	width: 100%;
        	height: 100%;
        }
        
        /*任务七、给导航设置3D前，与3D后变形效果*/
        .front {
        	transform:rotateX(0deg) translateZ(25px);
        	-ms-transform:rotateX(0deg) translateZ(25px);
        	-o-transform:rotateX(0deg) translateZ(25px);
        	-moz-transform:rotateX(0deg) translateZ(25px);
        	-webkit-transform:rotateX(0deg) translateZ(25px);
         }
        
        .back {
        	transform:rotateX(-90deg) translateZ(25px);
        	-ms-transform:rotateX(-90deg) translateZ(25px);
        	-o-transform:rotateX(-90deg) translateZ(25px);
        	-moz-transform:rotateX(-90deg) translateZ(25px);
        	-webkit-transform:rotateX(-90deg) translateZ(25px);
          color: #FFE7C4;
        }
        
        .front, .back {
          display: block;
        	width: 100%;
        	height: 100%;
        	position: absolute;
        	top: 0;
        	left: 0;
        	background: #74adaa;
        	padding: 15px 30px 15px 31px;	
        	color: white;
        	-webkit-pointer-events: none;
          -moz-pointer-events: none;
          -ms-pointer-events: none;
          -o-pointer-events: none;
          pointer-events: none;
          -webkit-box-sizing: border-box;
          box-sizing: border-box;
        }
        /*任务八、设置导航当前状态与悬浮状态下的背景效果*/
        .nav-menu li .active .front,
        .nav-menu li .active .back,
        .nav-menu li a:hover .front,
        .nav-menu li a:hover .back {
        	background-color: #51938F;
        	background-size: 5px 5px;
        	background-position: 0 0, 30px 30px;
        	background-image: -webkit-linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480), linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480);
			  background-image: -moz-linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480), linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480);
				background-image: -ms-linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480), linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480);
			  background-image: -o-linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480), linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480);
			  background-image: linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480), linear-gradient(45deg, #478480 25%, transparent 25%, transparent 75%, #478480 75%, #478480);
        	/*background-image: -webkit-linear-gradient(45deg,#434238 25%,transparent 25%,transparent 75%,#434238 75%,#434238),-ms-linear-gradient(45deg,#434238 25%,transparent 25%,transparent 75%,#434238 75%,#434238),-moz-linear-gradient(45deg,#434238 25%,transparent 25%,transparent 75%,#434238 75%,#434238),-o-linear-gradient(45deg,#434238 25%,transparent 25%,transparent 75%,#434238 75%,#434238),linear-gradient(45deg,#434238 25%,transparent 25%,transparent 75%,#434238 75%,#434238);*/
        }
        .nav-menu ul {
          position: absolute;
        	text-align: left;
        	line-height: 40px;
        	font-size: 14px;
        	width: 200px;
        	-webkit-transition: all 0.3s ease-in;
          -moz-transition: all 0.3s ease-in;
          -ms-transition: all 0.3s ease-in;
          -o-transition: all 0.3s ease-in;
          transition: all 0.3s ease-in;
          -webkit-transform-origin: 0px 0px;
          -moz-transform-origin: 0px 0px;
          -ms-transform-origin: 0px 0px;
          -o-transform-origin: 0px 0px;
          transform-origin: 0px 0px;
          -webkit-transform: rotateX(-90deg);
          -moz-transform: rotateX(-90deg);
          -ms-transform: rotateX(-90deg);
          -o-transform: rotateX(-90deg);
          transform: rotateX(-90deg);
          -webkit-backface-visibility: hidden;
          -moz-backface-visibility: hidden;
          -ms-backface-visibility: hidden;
          -o-backface-visibility: hidden;
        	backface-visibility: hidden;
        }
        /*任务九、显示下拉导航菜单，并其设置一个变形效果*/
        .nav-menu > li:hover ul {
          display: block;
			-webkit-transform: rotateX(0deg);
			-moz-transform: rotateX(0deg);
			-ms-transform: rotateX(0deg);
			-o-transform: rotateX(0deg);
			transform: rotateX(0deg);          
         }
